Permeance and latex paint
Martin et al.,
I have a question for a “Pro” on this blog. I am looking into different encapsulants or paints to go over lead paint in an older home remodel. The permeance for these latex based encapsulants varies widely.
In general, not considering the lead control aspects, would a lower permeance be better than a higher permeance? Since this is an older home, we are not talking about new construction materials, choosing a WRB, etc. Rather, we are trying to limit lead hazards and put a coating on the wall that will not create an additional problem of moisture build up in the wall which could lead to rotting or potentially encouraging molds.
I am considering a latex paint with a permeance of 2.894 perms by dry cup. This is just under the low range of most latex paints from a table I found at Building Science Corp. My thought is this would be a good choice as it would limit moisture moving through the paint, but not so much as to cause a moisture build up. The answer to this may also depend on climate/geography.
What do you all think about this?
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